During the 4th Step process, my sponsor suggested a few inventories that I hadn't thought to do myself. One was on my fear of relapse. He had heard me say that I was worried about what would happen if I lost my sobriety, hence the suggestion.... and, since I had already made the commitment to myself and to God that I was going to do whatever my sponsor said no matter what, his suggestion was as good as a requirement.
That inventory had a real impact on how I saw myself and how I saw God. It brought out a large number of my character defects that I still needed to become willing to have God remove (Step 6).
That inventory showed me I still wasn't really accepting my powerlessness over lust. I was still holding onto the delusional thinking that I had to have some power over lust or I was going to relapse. But the truth is that if I am the one who must be in control of lust, I certainly will act out again. But since I am powerless over lust, when I surrender to a Power greater than myself, He gives me the gift of sobriety.
Does that fear ever return? Of course! Like lust temptations, it keeps turning up. The difference now is that when that fear shows up again, I can recognize it for what it really is (tell myself the truth about it), and I can surrender it as well. I can connect with God in the midst of my weaknesses, and He does for me what I can't do for myself. Choosing to trust God is the solution to my fear of relapse (and to my other fears as well).